I would ask how much shooting have you done with these guns? What kind of performance are you getting with your guns?
I would suggest that you really look at how much shooting you've done and what kind of performance you're getting before looking into any kind of custom modifications. When considering some kind of modification, ask yourself, "What problem/issue is this addressing?"
I'm not against doing custom work on a carry gun, but I think it's best to have a good idea of what you want to achieve. Speaking from experience, I've had custom work done on a 1911 before I really knew what I wanted/needed. While the results were satisfactory, the gun would likely be better off if I had given it some thought before modifying it for the sake of modifying it.
With that said...
As was mentioned, sights and grips are a good place to start. I prefer simple sights. Either plain black, plain black rear/colored front, or plain black rear/tritium front. I think night sights can be useful, but don't believe they're essential. That said, my EDC PX4 Compact has a plain black rear sight with an orange and tritium front sight.
If the grips are less than satisfactory, there are options. Stippling can be good, but it's also permanent. I'm a fan of Talon Grips. I think they're effective without adding much bulk. Slip-on grips can be useful, but my experience with them is limited.
You mentioned the trigger. It's fine to have a trigger job done, but again, is it really going to be enough to improve your performance? Now, if the trigger pull is gritty, or maybe extraordinarily heavy, some minimal work to smooth and lighten can be effective. Personally, I'm not a fan of spring kits, but I know they can be helpful for some people. 3 suggestions for the trigger: 1) safety must not be compromised, 2) reliability must not be compromised, and 3) keep the trigger pull within factory specs.
Regarding match barrels...
For the most part, I don't believe they're necessary on a defensive pistol. Most people who don't shoot guns for a living, myself included, can't shoot a factory barreled gun to it's full potential, let alone a match barrel. Any difference in resulting accuracy is likely to be insignificant for us mere mortals. One possible exception I can think of is if the factory barrel is just so loose that it negatively impacts reliability and/or shootability. Having a match barrel fitted could fix that, but so could properly installing/fitting a regular factory barrel.
Now, if you just have to have a match barrel, regardless of whatever benefit it may or may not provide, make sure safety and reliability aren't compromised.
TL;DR: Custom modifications are best made when they address actual problems/issues one may have with a particular gun.
Just my opinion.
